I have a colllectionView running successfully which grabs url image content from web link .I am trying to populate collectionView at random index once every time view loads.my try as below...
override func viewDidLoad() {
super.viewDidLoad()
self.collectionView.reloadData()
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "Cell", for: indexPath as IndexPath) as! Cell
let randomIndex = Int(arc4random_uniform(UInt32(apps.count)))
cell.app = apps[randomIndex] as? AppInfo
return cell
}
Above method reload the collectionView everytime page scrolls. I am trying to achieve reload once only...
Thanks in Advance....
Related
I would like to change my entier array used to created all my cells with a button and then reload my collection view, but it is not working. I've tried to reload the collection view into the main thread but it also not working
I've tried to reload the collection view into the main thread, or just using collectionView.reloadData() but it also not working
#IBAction func BicepsBtn(_ sender: Any) {
self.current = "Biceps"
Data = user.getMuscleDataChart(typeMuscle: current)
listMuscle = user.getListMuscle(typeMuscle: current)
collectionView.reloadData()
}
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return listMuscle.count
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "cell", for: indexPath)
let switchView = cell.viewWithTag(1000) as? UISwitch
let titleView = cell.viewWithTag(1001) as? UILabel
if let titleView = titleView, let switchView = switchView {
titleView.text = self.listMuscle[indexPath.row].label
titleView.textColor = self.listMuscle[indexPath.row].color
switchView.tag = indexPath.row
switchView.addTarget(self, action: #selector(yourFunc),
for: UIControl.Event.valueChanged)
}
return cell
}
Here is my current code, when the user is going to click on the Biceps button, the function will fetch all data about this muscle and then trying to reload.
Any idea ?
Thanks in advance
I have a tableView and collectionView in one view controller.
in tableView I have title description and in collectionView I have lable .
I want on collectionView label selection tableView content should change .
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return Bookmark.count
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionViewBookmark.dequeueReusableCell(withReuseIdentifier: "cell", for: indexPath) as! BookMarkCollectionViewCell
cell.lblTitle.text = Bookmark[indexPath.row]
cell.backgroundColor = UIColor.white
return cell
}
func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
let cell = collectionViewBookmark.cellForItem(at: indexPath)
cell?.backgroundColor = UIColor.blue
self.selectedIndexPath = indexPath
//
let newsDict = arrNewsData[indexPath.row]
if (indexPath.row == 1)
{
let cell1 = tableViewBookMark.cellForRow(at: indexPath) as! BookMarkFirstTableViewCell
cell1.lblTitle.text = newsDict["title"] as! String
tableViewBookMark.reloadData()
}
tableViewBookMark.reloadData()
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableViewBookMark.dequeueReusableCell(withIdentifier: "cell", for: indexPath) as! BookMarkFirstTableViewCell
let dict = arrNewsData[indexPath.row]
cell.lblTitle.text = dict["title"] as! String
// cell.imgBookMark.image = dict["image_url"]
let url = URL(string: dict["image_url"] as! String)
URLSession.shared.dataTask(with: url!) { (data, response, error) in
if data != nil{
DispatchQueue.main.async {
let image = UIImage(data: data!)
cell.imgBookMark.image = image
}
}
}.resume()
return cell
}
See my inline comments.
var tempCell: BookMarkFirstTableViewCell?
//Inside cellForRowAt indexPath
tempCell = cell
//Inside (collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath)
tempCell.lblTitle.text = newsDict["title"] as! String
You're reloading the tableView after updating the values in the cell,
tableViewBookMark.reloadData()
This will trigger the data source function including cellForRowAt, so you will lose your updated values a solution to this is to have a global variable in the UIViewController and check its values inside the cellForRowAt and update it in the collectionView DidSelect .
Extra tip: you don't need to reload all the tableView for a single change you can use
tableView.reloadRows(at: [indexPath], with: .top)
to reload only number of selected cells in the tableView
I've been looking for a way to reload my collection view header. So I have a collection view header & a CollectionViewCell that only contains an image. Now when the cell is press, I would like to display the image in the header view without calling collectionView.reloadData(). This is how my didSelectItemAt & didDeselectItemAt method looks like.
override func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
selectedImage = images[indexPath.item]
let imageCell = collectionView.cellForItem(at: indexPath) as! CollectionCell
imageCell.photoBackgroundView.backgroundColor = .red
collectionView.reloadData()
}
override func collectionView(_ collectionView: UICollectionView, didDeselectItemAt indexPath: IndexPath) {
let imageCell = collectionView.cellForItem(at: indexPath) as! ImagePickerCell
imageCell.photoBackgroundView.backgroundColor = .black
}
So when I select a cell the view turns red, when I deselect it the view turns black. This video here, shows how the behavior without reloading the collectionView. Now here is were I would like to reload the header view.
If I do use collectionView.reloadData(), this is the outcome. How would I be able to reload the header or the collectionView where the header view displays the selected cell image & turns red.
You can try like global instance for that. Like
class YourClass: UIViewController {
/// Profile imageView
var profileImageview = UIImageView()
}
In CollectionView cellforItem assign a imageview. Like
let imageCell = collectionView.cellForItem(at: indexPath) as! CollectionCell
profileImageview = imageCell.imageView
Then when every you selecting collectionViewCell
You can call a function to change a image of imageView. Like
func updateImage() {
profileImageview.image = UIImage()
}
Well I'm trying to understand why sometimes you cast the cell in CollectionCell and sometimes in ImagePickerCell, anyway try to change your functions in these
func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
let cell = collectionView.cellForItem(at: indexPath) as! CollectionCell
cell?.photoBackgroundView.backgroundColor = .red
}
func collectionView(_ collectionView: UICollectionView, didDeselectItemAt indexPath: IndexPath) {
let cell = collectionView.cellForItem(at: indexPath) as! CollectionCell
cell?.photoBackgroundView.backgroundColor = .black
}
I got a collection view with 2 different sections. I want to tap a cell in one of the sections and pass the text in that cell to a text view, which is in a separate cell in its own section.
This is what I tried so far, but nothing happened. I am trying to send the notes data to another cell. I can print the data when the cell is tapped.
Updated: This is the cell with the text view that I want to pass the selected cell data to.
// cell that I am trying to passing data to
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = myCollectionView.dequeueReusableCell(withReuseIdentifier: "notesView", for: indexPath) as! TestViewCollectionViewCell
cell.myTextView.text = .....
return cell
}
// Cell that I am passing data from
func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
if indexPath.section == 0 {
// Cell that I want to send data to
let cell = myCollectionView.dequeueReusableCell(withReuseIdentifier: "notesView", for: indexPath) as! TestViewCollectionViewCell
let myNotes = notes[indexPath.row]
cell.myTextView.text = myNotes.textView
}
}
Here is the way you can correct that:
func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
if indexPath.section == 0 {
//First get your selected cell
if let cell = collectionView.cellForItem(at: indexPath) as? TestViewCollectionViewCell {
//Now get selected cell text here
//update your section two array with new values
//Reload your collection view.
} else {
// Error indexPath is not on screen: this should never happen.
}
}
}
I just updated to Swift 3.
My collection views were working great before the update. I did the recommended changes to make the compiler happy, but now I'm having this problem.
Image views that are in my custom UICollectionViewCells are simply not appearing anymore. Neither programmatically generated image views nor prototype image views are appearing.
I've given the image views background colors to check if my images are nil. The background colors aren't appearing, so it is safe to assume the image views are not appearing at all.
The cells themselves ARE appearing. Each image view has a label underneath, and the label is displaying properly with the correct text.
The most confusing part is that sometimes the image views DO appear, but there seems to be no rhyme or reason as to why or when.
My code is pretty standard, but I'll go ahead and share it anyway:
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return searchClubs.count
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell: HomeCollectionViewCell = collectionView.dequeueReusableCell(withReuseIdentifier: "cell", for: indexPath) as! HomeCollectionViewCell
cell.barLabel.text = searchClubs[indexPath.row].name
cell.imageCell.image = searchClubs[indexPath.row].image
cell.imageCell.layer.masksToBounds = true
cell.imageCell.layer.cornerRadius = cell.imageCell.frame.height / 2
return cell
}
func feedSearchClubs(child: AnyObject) {
let name = child.value(forKey: "Name") as! String
//Image
let base64EncodedString = child.value(forKey: "Image")!
let imageData = NSData(base64Encoded: base64EncodedString as! String, options: NSData.Base64DecodingOptions.ignoreUnknownCharacters)
let image = UIImage(data:imageData! as Data)
//Populate clubs array
let club = Club.init(name: name, image: image!)
self.searchClubs.append(club)
DispatchQueue.main.async {
self.collectionView.reloadData()
}
}
Since Xcode 8 you have to call layoutIfNeeded() to calculate size (in your case you need to know cell.imageCell.frame.height) and position from auto layout rules or use a fixed value of cornerRadius.
cell.imageCell.layoutIfNeeded()
cell.imageCell.layer.masksToBounds = true
cell.imageCell.layer.cornerRadius = cell.imageCell.frame.height / 2
OR
cell.imageCell.layer.masksToBounds = true
cell.imageCell.layer.cornerRadius = 5
The imageCell's frame isn't set up ready yet in the cellForItemAt method.
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell: HomeCollectionViewCell = collectionView.dequeueReusableCell(withReuseIdentifier: "cell", for: indexPath) as! HomeCollectionViewCell
cell.barLabel.text = searchClubs[indexPath.row].name
cell.imageCell.image = searchClubs[indexPath.row].image
return cell
}
Instead put the setting up of layer on willDisplay since cell.imageCell.frame.height will have its value.
func collectionView(_ collectionView: UICollectionView, willDisplay cell: UICollectionViewCell, forItemAt indexPath: IndexPath) {
let cell: HomeCollectionViewCell = collectionView.dequeueReusableCell(withReuseIdentifier: "cell", for: indexPath) as! HomeCollectionViewCell
cell.imageCell.layer.masksToBounds = true
cell.imageCell.layer.cornerRadius = cell.imageCell.frame.height / 2
}